Health Library

What Are the Symptoms of Colorectal Cancer?

People with colorectal cancer often do not have symptoms right away. By the time symptoms appear, the cancer may have grown or spread to other organs, which may make treating it harder. That’s why routine screening is important.

As cancers in the colon and rectum grow, warning signs may arise. You should tell your health care provider and get prompt medical attention if you notice any of these signs:

A change in bowel habits that lasts for more than a few days, including diarrhea, constipation, or a sensation that your bowel is still not empty after a bowel movement

Bright red or very dark blood in your stool

Constant tiredness

Stools that are thinner than usual

Stools that appear slimy or that have a mucous film on them

Persistent gas pains, bloating, fullness, or cramps

Unexplained weight loss

Vomiting

These symptoms may be caused by colorectal cancer or by other, less serious conditions. It is important to check with your health care provider to be sure.